Android activity 函数调用之间的生命周期混淆

Question

当我运行这个应用程序时，我首先得到 "On Resume" 而不是 "On start" 甚至 "On create" 都没有出现，请告诉我为什么？ "On Restart" toast 未显示，但测试正在更新。
public class MainActivity 扩展 AppCompatActivity {

    public int test=0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toast t=Toast.makeText(getApplicationContext(),"On create",Toast.LENGTH_SHORT);
        t.setGravity(Gravity.CENTER_VERTICAL,20,20);
        t.show();
    }

    @Override
    protected void onRestart() {
        super.onRestart();
        Toast t=Toast.makeText(getApplicationContext(),"On restart",Toast.LENGTH_LONG);
        t.setGravity(Gravity.CENTER_VERTICAL,20,20);
        TextView num=(TextView) findViewById(R.id.textNum);
        test++;
        num.setText(String.valueOf(test));
        t.show();
    }

    @Override
    protected void onStart() {
        super.onStart();
        Toast.makeText(getApplicationContext(),"On start",Toast.LENGTH_SHORT).show();
    }
    @Override
    protected void onResume() {
        super.onResume();
        Toast t=Toast.makeText(getApplicationContext(),"On resume",Toast.LENGTH_SHORT);
        t.setGravity(Gravity.CENTER_VERTICAL,10,20);
        t.show();
    }

    @Override
    protected void onPause() {
        super.onPause();
       Toast t= Toast.makeText(getApplicationContext(),"On Pause",Toast.LENGTH_SHORT);
       t.setGravity(Gravity.CENTER_VERTICAL,20,20);
       t.show();
    }

    @Override
    protected void onStop() {
        super.onStop();
        Toast.makeText(getApplicationContext(),"On Stop",Toast.LENGTH_SHORT).show();
    }


    @Override
    protected void onDestroy() {
        super.onDestroy();
        Toast.makeText(getApplicationContext(),"On destroy",Toast.LENGTH_SHORT).show();
    }
}

Answer 1

使用Toast作为调试方法真是个坏主意。使用日志记录并查看您的 logcat。您将看到这些方法按照它们应有的顺序被调用。只是不要这样做。

Android activity 函数调用之间的生命周期混淆

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